Random issue that I wanted to throw out there and see if anyone else was having with their Series X.
I did a clean install of Mortal Kombat 11 and all the DLC I owned. For whatever reason some of it isn't showing up even though its "installed". And it seems entirely scattershot. So from KP1, Spawn shows up, but Joker, Nightwolf, etc all say "Press A to Purchase" on the character select screen.
Same with cosmetic. My klassic ninja pack doesn't populate in my wardrobe, but the day of the dead Liu Kang from another costume pack does...weird.